ARG1 and type 1 diabetes mellitus: The data revealed that the iNOS protein expression was upregulated in T1DM mice on D14 (Figure 3(b); P = 0.0007, n = 5) while Arg-1 was not altered (Figure 3(b); P = 0.1708, n = 5), suggesting a significant increase of M1 microglia in the spinal cord of diabetic mice.